A riding buddy of mine just bought a Kona Explosif hardtail that he uses as a modern full sized dirt jumper. It's a bit new skool in that it has 27.5" wheels (which will incidentally make it a bunch more of a functional trail bike) but still has a really tight rear triangle and a pretty whippy front end to suit pump track or trials type riding. He LOVES the thing.
Also, just FYI, Santa Cruz does sell a built version of the Jackal.